QM: system with two lin. independent states

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[SOLVED] QM: system with two lin. independent states

Homework Statement



Imagine a system with just two linear independent states:

|1>=(1,0) and |2>=(0,1) (these are actually column matrices, but I don't know how to type those in tex)

|\Psi>=a|1>+b|2>=(a,b), also |a|^2+|b|^2=1

suppose the hamiltonian is a 2x2 matrix with entries j,g above and g,j below, (g,j \in R>0).

The time-independent schroding equation reads

H |\Psi>=i h/(2 pi) d/dt(|\Psi>)

a) find the eigenvalues and eigenvectors of this hamiltonian
b) suppose the system starts out at t=0 in |1>, what is the state at time t?

The Attempt at a Solution



I thought of solving the time-independent SE;

ja+gb= i h/(2 pi) d/dt(a)
ga+jb= i h/(2 pi) d/dt(b)

but does this mean g=0? And if so, how do I get any further. I'm stuck.
 
Last edited:
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Change to the basis where H is diagonal.
 
solved it with a friend today =)
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
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